(Brief because (a) I really don’t know that much history, and (b) there’s really only one idea here with a few examples, and once you get the point, we’re done and can move to the outro.)

Astronomy and Celestial Mechanics were dangerous ideas because they undermined the most powerful organization of their day, The Church. That’s why people have been banned, tortured, and burned at the stake for talking about these ideas.

Crossbows were a dangerous idea because they allowed an untrained peasant to kill a knight. Longbows were not a dangerous idea, because only trained archers can kill a knight with a longbow, and the nobility were the only people who could compel peasants to practise yeomanry.

Cryptography is not a dangerous idea, because we really don’t know if any of our algorithms and protocols are resistant to the NSA. This was hi-lighted when researchers “discovered” differential cryptanalysis. When they looked at the DES algorithm IBM has been promoting since the 1976, they found that it had been specifically tuned to resist differential cryptanalysis. IBM ‘fessed up: the US government had told them to tune things that way without explaining why, leading us to conclude they had known about this attack for decades before it became public knowledge. Today, we have no idea whether what we think is strong is actually strong or whether it has vulnerabilities and back doors governments can exploit.

Miles Davis was a walking, talking, trumpet-playing dangerous idea. Not because he reinvented Jazz five different times (Dear Steve: Apple II, Macintosh, iPod/iPhone, Pixar. One more for the tie, two for the record.) Miles was an egocentric, venal man who worked the system, not undermined the system. But he was still dangerous because he got white people directly interested in black music. There was no Elvis or Vanilla Ice or anyone else between his music and the mainstream audience. For a government intent on keeping America’s two dominant cultures divided through fear, anything uniting them was a threat.

People say Miles’ legacy is his music. To me, Miles’ lasting legacy is people like me, people with one parent from each culture who grew up dancing to the same music together. People who, incidentally, do not vote for governments that take a divide and conquer approach to culture.

And on to tech. Microcomputers were not a dangerous idea. But personal computers were dangerous. It took decades for IT departments to regain control over people bringing their own computers to work. They can thank Microsoft for helping them get back into the driver’s seat.

(This, incidentally, is why I really dislike Microsoft’s policies: it has nothing to do with their lack of taste, it has to do with their mission to make the computer on my desk belong to my IT department or the record label or the movie studio or—I suspect—the government.)

Web applications are dangerous. Never mind the fact that they make desktop applications obsolete. The people who built desktop applications just go and get jobs writing web applications. Same people, different shit. But as Giles Bowkett pointed out, web applications just might make venture capital obsolete! When you don’t need hundreds of programmers and distribution channels and all the other friction-managing elements of a company that ships old-school software, you need a lot less money to start a business.

And on to media. You know that the web is busy putting newspapers out of business. My wife and I watched YouTube last Saturday Night. I’m not talking about the advertising business: I think we would have been happy to watch ads to watch our Mitch Hedberg and Billy Connoly comedy clips. But the web lets us choose what we want to watch, when we want to watch it. The network can’t put their up-and-coming show on right after their hit to give it a boost. The new show has to compete on its own merits. That puts users in control, and that’s dangerous.

Joel Spolsky said a similar thing about pricing all music at 99 cents a track: it means the labels can’t kill an artist by sticking their CD in the $3.99 crapola bin. Users choose what they want to listen to. That’s dangerous, again because users are in control.

Okay, that’s enough. Dangerous ideas are the ones that subvert the existing hierarchy of control, not just the ones that shuffle people around in the same old chairs. Apple Macintosh with a GUI replacing a PC with a command line? Not dangerous. Apple Macintosh with a Laserwriter and Aldus Pagemaker allowing someone to launch a magazine in their basement that competes with a company employing dozens of layout artists? That’s dangerous, and that’s interesting.

Dangerous equals subversive equals interesting.

outro

Deep breath. Okay, the next thing is not particularly dangerous for the world at large, but it is for me. I am retiring from blogging and retiring from hacking on Ruby. Maybe I’ll un-retire one day. I don’t know, the future is not set.

Miles Davis wasn’t afraid to move on when the time was right, even if what he was doing seemed to make people happy. Respecting his legacy means seeking what he sought.

Remember how I said that microcomputers were not dangerous, but personal computers were? Right now, I would say this: Ruby is not dangerous, but Rails is dangerous and Merb is dangerous and Sinatra is dangerous. Rewriting for Ruby is interesting. I believe it is useful. But is it dangerous? No.

Likewise, I can say with a clear conscience that while writing is gratifying, and trying to write out and explain ideas has helped me understand things, the writing I’ve been doing is not dangerous. It doesn’t subvert.

So while hacking away on Ruby the language and blogging about software development is gratifying and useful, they are not dangerous activities. They are microcomputers, but they are not personal computers.

I am going on vacation from August 2nd through 10th. During that time I plan to do absolutely no thinking about computers. For what it’s worth, I will be engaging in activities with faux danger: wreck diving and sport climbing. (p.s. these are not solitary pursuits: if you want to try some of the world’s greatest wreck diving and sport climbing, get in touch).

When I return, I will give things some serious thought and hopefully, discover a way I can help make our world a more dangerous place.

Thank you ever so much for your support and interest and feedback. Especial thanks to my fellow bloggers like Joel, Joey, Giles, Damien, Obie and so many others who exchanged ideas with me and kept the debate alive. And Reddit? And Hacker News? You rock, you are the future. I can’t wait to see how your communities and technologies evolve.

"For a government intent on keeping America’s two dominant cultures divided through fear"

The government of the time would not be able to think of this, would not be able to implement it. Some local politicians ran on racial fears; pumping them up during elections. But the gov't didn't have any idea how to generate the racism in the first place.

I sincerely hope this will result in another approach to sharing your thoughts and insights, but that's selfish of me.

I've been SCUBA diving for a bit under 10 years now, but mostly do shore dives (univer$ity happened), including wrecks and stuff. I do this mostly in Ontario. I'd love to get together some time. I would even be willing to completely ignore the software field during diving trips if you wish so. The diver's hand signs are not ideal to talk about abstractions anyway ;-)

And Miles Davis didn’t invent the music he popularized, either. he had an ear for what was next and an amazing talent for recruiting young and talented musicians that blossomed under his leadership. Miles and Steve have a lot in common.

I beg to differ with your statement that your writing was not dangerous. You upended a lot of conventional wisdom that the powerful had a lot invested in. I hope that your next venture is at least as influential and subversive.

I'm curious why your decision to blog or not is based on whether it is, as you put it, dangerous. Is it a time issue - you only have time for so much, and you want to devote more of your time to revolutionary activities? Or was this blog always intended to promote dangerous ideas, and you feel it is no longer serving that purpose?

Likewise with hacking Ruby. Is it time, or something else?

I ask because my own attempts at subverting the status quo are mostly orthogonal to my tech interests, and I'm trying to better understand where you are coming from.

This weblog has always been devoted to the idea of programming as an act of passion. I perceived that in my own life and in many other programmer’s lives the industry had leeched a lot of the passion out of it, and I wanted to inject a little passion back into the system.

Now it is simply time for me to turn my attention elsewhere, to another kind of change. My aim is to use my programming interests, but that is not the same thing as writing about or evangelizing those interests directly.

Reg I've enjoyed your posting greatly: you managed to stay consistently a cut above in your explorations of what code is doing and your explorations have set a great model of what a technical blog could be. There are hordes of pundits talking about platforms and languages, but your discourse on metaprogramming has been transcendent: you consistently focused on what code was doing and how through metaprogramming we could alter that environment. That connected deeply with me even though I am not a Ruby programmer. There are very few people with your talent for both exploring and explaining how code works, and you did both with style and engaged curiosity. Thank you for all your wonderful contributions.

Your articles have always been great, and there hasn't been a single thing that I've read from you that was without substance.

Though you think some of your writing might not have been dangerous, you under estimate how tamed we are these days, and how low a barrier we have before some of us can look at something as "dangerous".

Trade unions are also dangerous. The idea that the proles should be able to organize and negotiate the terms of the compensation for their product (labor) is abhorrent to the elite, and despite affirmation by the courts and Congress has been utterly crushed and driven from our minds.

Thank you for your all the craft you have shared with us. I would really miss your writings - both the style and the crunch. And I cannot help hoping that one morning my feed reader would be saying "raganwald (1)", hiding something other than delicious links.

For what its worth, I think your writing falls squarely in that 1% of software development blogs that ARE remotely dangerous. I have found your writing to be a great positive influence. I hope that one day I will be able to communicate my own ideas with a similar degree of skill.